This invention relates to toilet assemblies used in waste disposal systems on passenger vehicles such as buses, trains and aircraft. A preferred embodiment of a waste disposal system for railcars is described and claimed in a co-pending application, incorporated herein by reference, Ser. No. 07/862,320 (our reference NORCAN.004A) filed on the same date as the present invention and assigned to the assignee of the present invention.
The main components of such a toilet assembly are a flush valve assembly, a toilet bowl, a spray ring, a support base and a flush control unit.
In the prior art toilet assemblies, each of these components are relatively heavy and in the case of flush valve assemblies, require numerous moving parts. For instance, these prior flush valves typically incorporate motors or pneumatically driven valves having many relatively heavy moving parts. In addition, these assemblies are prone to frequent breakdowns and constant maintenance. The prior art toilet bowls are made from relatively heavy, as well as expensive stainless steel. Likewise, the prior art support bases typically comprise vertical legs typically made from steel.
The prior art toilet assemblies have additional disadvantages besides excessive weight and complexity. One disadvantage is that the prior art spray rings are formed from stainless steel tubing. When the spray holes become clogged, which is not infrequent due to lime and calcium deposits from local water sources, a chemical cleaning of the tube is required since the spray ring may not be quickly and inexpensively replaced.
Another disadvantage is that the structural configuration of the prior art support bases expose the toilet assembly to excessive tipping forces since the prior art support bases are connected at or close to the bottom of the bowl. These tipping forces are further accentuated due to the fact that the prior art support bases are not positioned under the center of gravity of the whole toilet assembly. Rather the prior art bases are positioned under the center of gravity of the bowl and fail to take into account the additional weight of the components attached to the rear of the bowl. Furthermore, the attachment of the bowl to the prior art support base requires that additional thicknesses of material (doublers) are needed on the exterior surface of the bowl for allowing the bowls to be attached to the prior art base, thus further increasing the weight of the toilet assembly.
A further disadvantage of the prior art toilet bowl assembly is that the vertical legs of the prior art support base restrict the work space between the shroud and the front of the support base.